RFID enabled metal transaction cards

Abstract

A transaction card (smartcard) having a front “continuous” (with no slit) metal layer (ML, FML, 930, 1130 ) with an opening ( 912, 1112 ) for a dual-interface transponder chip module (TCM, 910, 1110 ) having a module antenna (MA, 911, 1111 ) on its bond side (not shown). A magnetic shielding layer (MSL, 942, 1142 ) comprising ferrite material disposed below the front face continuous metal layer. An amplifying element, booster antenna circuit (BAC, 944, 1144 ) disposed under the magnetic shielding layer. A rear discontinuous metal layer (ML, DML, 950, 1150 ) with a slit (S, 920, 1120 ) and a metal ledge ( 916, 1116 ) surrounding a module opening (MO, 914, 1114 ) to function as a coupling frame (CF). A rear plastic layer ( 960, 1160 ) formed of non-RF impeding material may capture a magnetic stripe and security elements (signature panel and hologram). A portion of the front face continuous metal layer may protrude downward into the magnetic shielding layer and booster antenna circuit layer. The rear discontinuous metal layer may have an additional slit to regulate the activation distance.

What is claimed is: 
     
       1. A smartcard, capable of at least contactless operation, comprising:
 a front face continuous metal layer (ML, CML,  930 ,  1130 ) without a slit and having a first module opening (MO,  912 ,  1112 ); 
 a rear discontinuous metal layer (ML, DML,  950 ,  1150 ) having a metal ledge ( 916 ,  1116 ) surrounding a second module opening (MO,  914 ,  1114 ) and a slit (S,  920 ,  1120 ); 
 a transponder chip module (TCM,  910 ,  1110 ) with a module antenna (MA,  911 ,  1111 ); and 
 an assembly of a magnetic shielding layer (MSL,  942 ,  1142 ) and a booster antenna circuit (BAC,  944 ,  1144 ) disposed between the front face continuous metal layer and the rear discontinuous metal layer; 
 wherein: 
 the booster antenna circuit (BAC) comprises a perimeter coil (PC,  944 A,  1144 A) and a coupler coil (CC,  944 C,  1144 C); and 
 the booster antenna circuit comprises a closed loop circuit with no open-ended antenna elements; 
 further comprising: 
 an integrated parallel plate capacitor bank comprising upper electrodes (UE,  1044 D) and lower electrodes (LE,  1044 E) attached in parallel to the perimeter coil and coupler coil for frequency trimming. 
 
     
     
       2. The smartcard of  claim 1 , wherein:
 the magnetic shielding layer is disposed behind the front face continuous metal layer; and 
 
       the booster antenna circuit is disposed behind the magnetic shielding layer. 
     
     
       3. The smartcard of  claim 1 , wherein:
 the rear discontinuous metal layer (DML) with a slit(S) which terminates in a module opening (MO), is provided with at least one additional slit ( 1120 B) arranged on another (such as the opposite) side of the discontinuous metal layer (to enhance the activation distance). 
 
     
     
       4. The smartcard of  claim 1 , wherein:
 at least some windings of the perimeter coil overlap the slit. 
 
     
     
       5. The smartcard of  claim 1 , further comprising:
 a metal ledge surrounding the second module opening; wherein the coupler coil overlaps the metal ledge. 
 
     
     
       6. A smartcard, capable of at least contactless operation, comprising:
 a front face continuous metal layer (ML, CML,  930 ,  1130 ) without a slit and having a first module opening (MO,  912 ,  1112 ); 
 a rear discontinuous metal layer (ML, DML,  950 ,  1150 ) having a metal ledge ( 916 ,  1116 ) surrounding a second module opening (MO,  914 ,  1114 ) and a slit (S,  920 ,  1120 ); 
 a transponder chip module (TCM,  910 ,  1110 ) with a module antenna (MA,  911 ,  1111 ); and 
 an assembly of a magnetic shielding layer (MSL,  942 ,  1142 ) and a booster antenna circuit (BAC,  944 ,  1144 ) disposed between the front face continuous metal layer and the rear discontinuous metal layer; 
 wherein: 
 the module antenna (MA,  911 ,  1111 ) of the transponder chip module (TCM,  910 ,  1110 ) is arranged concentrically to overlap the coupler coil ( 944 C,  1144 C) of the booster antenna circuit (BAC,  944 ,  1144 ) and a metal ledge ( 916 ,  1116 ) surrounding the module opening (MO,  914 ,  1114 ) in the rear discontinuous metal layer ( 950 ,  1150 ). 
 
     
     
       7. The smartcard of  claim 6 , wherein:
 the booster antenna circuit (BAC) comprises a perimeter coil (PC,  944 A,  1144 A) and a coupler coil (CC,  944 C,  1144 C); and 
 the booster antenna circuit comprises a closed loop circuit with no open-ended antenna elements. 
 
     
     
       8. The smartcard of  claim 7 , wherein:
 at least some windings of the perimeter coil overlap the slit. 
 
     
     
       9. The smartcard of  claim 7 , further comprising:
 a metal ledge surrounding the second module opening; wherein the coupler coil overlaps the metal ledge. 
 
     
     
       10. The smartcard of  claim 6 , wherein:
 the underside of the front face continuous metal layer ( 930 ) has a protruding boss ( 932 ) which extends through the card assembly to the rear discontinuous metal layer ( 950 ). 
 
     
     
       11. The smartcard of  claim 10 , wherein:
 the protruding boss ( 932 ) adds weight to the smartcard, enhances a metal sound and provides for mechanical robustness. 
 
     
     
       12. The smartcard of  claim 6 ,
 wherein the module antenna (MA,  911 ,  1111 ) is disposed in the module openings. 
 
     
     
       13. The smartcard of  claim 12 , wherein:
 the transponder chip module has the module antenna (MA,  911 ,  1111 ) and contact pads (CP) for dual interface capability. 
 
     
     
       14. The smartcard of  claim 6 , wherein:
 the magnetic shielding layer is disposed behind the front face continuous metal layer; and 
 
       the booster antenna circuit is disposed behind the magnetic shielding layer. 
     
     
       15. The smartcard of  claim 6 , wherein:
 the rear discontinuous metal layer (DML) with a slit(S) which terminates in a module opening (MO), is provided with at least one additional slit ( 1120 B) arranged on another (such as the opposite) side of the discontinuous metal layer (to enhance the activation distance). 
 
     
     
       16. Smartcard, capable of at least contactless operation, comprising:
 a front face continuous metal layer (ML, CML,  930 ,  1130 ) without a slit and having a first module opening (MO,  912 ,  1112 ); 
 a rear discontinuous metal layer (ML, DML,  950 ,  1150 ) having a metal ledge ( 916 ,  1116 ) surrounding a second module opening (MO,  914 ,  1114 ) and a slit (S,  920 ,  1120 ); 
 a transponder chip module (TCM,  910 ,  1110 ) with a module antenna (MA,  911 ,  1111 ); and 
 an assembly of a magnetic shielding layer (MSL,  942 ,  1142 ) and a booster antenna circuit (BAC,  944 ,  1144 ) disposed between the front face continuous metal layer and the rear discontinuous metal layer; 
 wherein; 
 the booster antenna circuit (BAC) comprises a perimeter coil (PC,  944 A,  1144 A) and a coupler coil (CC,  944 C,  1144 C); and 
 the booster antenna circuit comprises a closed loop circuit with no open-ended antenna elements; 
 wherein: 
 outer windings of the perimeter coil are arranged to be as close as possible to an outer peripheral edge of the rear discontinuous metal layer; and 
 the outer windings of the perimeter coil are within 500 pm of the outer edge of the rear discontinuous metal layer. 
 
     
     
       17. The smartcard of  claim 16 , wherein:
 the magnetic shielding layer is disposed behind the front face continuous metal layer; and 
 
       the booster antenna circuit is disposed behind the magnetic shielding layer. 
     
     
       18. The smartcard of  claim 16 , wherein:
 the rear discontinuous metal layer (DML) with a slit(S) which terminates in a module opening (MO), is provided with at least one additional slit ( 1120 B) arranged on another (such as the opposite) side of the discontinuous metal layer (to enhance the activation distance). 
 
     
     
       19. The smartcard of  claim 16 , wherein:
 at least some windings of the perimeter coil overlap the slit. 
 
     
     
       20. The smartcard of  claim 16 , further comprising:
 a metal ledge surrounding the second module opening; wherein the coupler coil overlaps the metal ledge.